Electrical contact strip



April 1969 H. R. HAMEL ETAL 3,439,315

ELECTRICAL CONTACT STRIP Filed July 17, 1967 FIG.|

INVENTOR. #AIPOL-D R. HAMEL BY aeNe sr 14 0/572;

/4 7'70/PNEY8 April 15, 1969 H. R. HAMEL ETAL ELECTRI CAL CQNTACT STRIPSheet Filed July 17, 1967 United States Patent US. Cl. 339-242 6 ClaimsABSTRACT OF THE DISCLOSURE An elongated electrical contact strip for usein a cube tap, and including first and second end to end receptacles.The first receptacle is formed by first and secondary substantiallycoplanar, transversely spaced apart side portions, which are offsetabove the longitudinal center plane of the strip and a first centerstrip portion interposed between the side portions, but disposed belowthe center plane. The first side portion includes first and secondoppositely disposed end portions, the center strip portion includesthird and fourth oppositely disposed end portions, and the second sideportion includes fifth and sixth oppositely disposed end portions, thefirst and fifth end portions being disposed at one end of the firstreceptacle, coplanar, and angled longitudinally outwardly and downwardlyto the center plane, and the third end portion disposed at said one endand angling outwardly and upwardly to the central plane.

The second receptacle is disposed at said one end of said firstreceptacle and includes third and fourth transversely spaced apart sideportions, substantially coplanar with the first center strip portion,and a second center strip portion substantially coplanar with the firstand second side portions. The third side portion includes seventh andeighth oppositely disposed end portions; the second center strip portionincludes ninth and tenth oppositely disposed end portions; and thefourth side portion includes eleventh and twelfth oppositely disposedend portions, the seventh end portion being coplanar with the first endportion and being joined with a portion thereof. The ninth end portionis coplanar with the third end portion, and a portion thereof is joinedtherewith, the remainder of the ninth end portion being joined with thefirst end portion. The eleventh end portion is coplanar with the fifthend portion, and a portion thereof joins therewith, the remainder of theeleventh end portion being joined with the third end portion.

BACKGROUND OF THE INVENTION Field of the invention The present inventionrelates generally to electrical cube taps and more particularly tocontact strips for use in such cube taps.

Description of prior art Many of the presently known cube taps formating with a plurality of plugs include contact strips and some ofthese strips form a plurality of plug prong receivable receptacles.Other known contact strips form receptacles which tightly receive theplug prongs, for example, the contact strips shown in Patents Nos.3,241,096 and 2,981,- 926. However, it is desirable to provide a contactstrip having a relatively short overall length and which holds the plugprongs firmly and securely.

Summary of the invention The contact strip of present invention includesfirst and second, end to end, plug prong receptacles. The firstreceptacle is formed by transversely spaced apart, substantiallycoplanar, first and second side portions that are raised from thecentral plane of the strip, and a first center strip portion depressedbelow such center plane. The second receptacle is formed by third andfourth side portions pressed below the center plane of the strip, and asecond center strip portion raised above the center plane. A particularadvantage of the strip of this invention is the arrangernent of theadjacent end portions of the first and second receptacles to enable theoverall length of the strip to be relatively short. One end portion ofthe first side portion extends downwardly to the center plane where partof it terminates and the remainder of it projects therebeyond and formsan end wall for the third side portion. The second center strip portionincludes an end wall adjacent the first receptacle that extendsdownwardly to the center plane where a portion of it joins theterminated part of the first side portion end wall, the remainder ofsuch center strip portion end wall projecting below the center plane andforming a portion of an end wall for the first center strip portion. Theremainder of the end wall of the first center strip portion terminatesat the center plane. The fourth side portion includes an end wall thatangles upwardly to the center plane where a portion of it joins with theterminated remainder of the first center strip end portion, and theremainder of such wall projects upwardly beyond the center plane to forman end wall for the second side portion.

Other features and the advantages of the present invention will beapparent from the following description, reference being had to theaccompanying drawings wherein a preferred embodiment of the invention isillustrated.

Brief description of the drawings FIG. 1 is a top view of an electricalcube tap including a pair of contact strips embodying the presentinvention;

FIG. 2 is a bottom view of the cube tap shown in FIG. 1;

FIG. 3 is a vertical sectional view, in enlarged scale, taken along line33 of FIG. 1;

FIG. 4 is a horizontal sectional view, in enlarged scale, taken alongthe line 4-4 of FIG. 3;

FIG. 5 is a side view, in reduced scale, of the cube tap shown in FIG.1, and showing the outline of an included contact strip in broken lines;

FIG. 6 is a top detail view, in further enlarged scale, of a contactstrip included in the cube tap shown in FIG. 1;

FIG. 7 is a side view taken along the line 7-7 of FIG. 6;

FIG. 8 is an end view taken along the line 8-8 of FIG. 6;

FIG. 9 is a vertical sectional view taken along the line 99 of FIG. 6.

Detailed description of the preferred embodiment Referring to FIGS. 1and 4, the electrical cube tap T includes a pair of contact strips Sembodying the present invention. The cube tap T includes two pairs ofplug prong receiving passages P extending in from its top side and asingle pair of such passages disposed intermediate the top pairs andextending in from the bottom side. Each of the strips S include three,end to end, plug prong receiving receptacles generally designated 21, 23and 25, one of such receptacles being aligned with each one of therespective passages P for receiving a plug prong, or blade (not shown),inserted into such passage.

Referring to FIGS. 1 through 4, the cube tap T is conveniently moldedfrom plastic, and includes a central longitudinal cooling cavity 31. Aparticular advantage of the strips S of this invention is that they arerelatively short, thus enabling the cube tap T to be relatively compact.

The strips S are conveniently pressed from a fiat strip of somewhatresilient, electrically conductive metal, the ends of such strip ofmetal remaining in the plane 33 (FIG. 7) of the unformed strip.Referring to FIGS. 4, 6 and 7, the right hand receptacle 21 of the stripS is formed by first and second spaced apart side portions 37 and 39,respectively, which are offset above the center plane 33 and a centerstrip portion 41 interposed therebetween and offset below the centerplane. The first side portion 37 is wider than the second side portion39 and is canted to slope outwardly and upwardly toward its outer edge43 to assist in leading a plug blade into the receptacle 21. The sideportion 37 includes oppositely disposed first and second end portions 45and 47, respectively, which slope longitudinally outwardly anddownwardly to the center plane 33. The second, or right, end portion 47joins, on its lower end, with an end band 51. The second side portion 39also includes first and second oppositely disposed end portions 53 and55, respectively, which angle longitudinally outwardly and downwardly tothe center plane 33 where the right end portion 55 joins with the endband 51. The center strip portion 41 includes oppositely disposed firstand second end portions 59 and 61, respectively, which anglelongitudinally outwardly and upwardly to the center plane 33 where theright end portion 61 joins with the end band 51.

The second, or middle, receptacle 23 is formed similar to the receptacle21 and includes opposite side portions 65 and 67, depressed below thecenter plane 33, such side portions being herein referred to as thirdand fourth side portions, respectively, to avoid confusion with theabove referred to first and second side portions 37 and 39,respectively. A center strip portion 68 is interposed between the sideportions 65 and 67 and is raised above the center plane 33. The thirdside portion 65 is narrower than the first side portion 37 and includesoppositely disposed end portions 69 and 71 which angle longitudinallyoutwardly away from each other and upwardly to the center plane 33. Itis a particular advantage of the strip S of this invention that the endportion 71 is in the same plane as the end portion 45, as best seen inFIGS. 6 and 7. The fourth side portion 67 includes a pair of oppositelydisposed end portions 73 and 75 which are coplanar with the end portions69 and 71 and, additionally, the end portion 75 is coplanar with the endportion 53 and is joined therewith. The section 79 of the end portionnot joined by the end portion 53 is joined with a section of the endportion 59. The wide side portion 67 is canted with the outside edge 80lowered (FIG. 9) to assist in leading the mating plug blade into thereceptacle 23.

The center strip portion 68 includes oppositely disposed end portions 81and 83 which angle longitudinally outwardly away from one another anddownwardly to the center plane 33. The right end portion 83 is coplanarwith the end portion 59 and is joined with a transverse portion thereof.The remainder 85 of the end portion 83 meets, and joins, with the endportion 45 at the level of the center plane 33.

The left hand receptacle 25, is formed similarly to the receptacle 21and includes opposite side portions 91 and 93 which are raised above thecenter plane 33and include respective pairs of outwardly and downwardlyangled end portions 95 and 97, and 99 and 101. The end portions 97 and101 are coplanar with, and joined, to the respective end portions 69 and73. The lower ends of the end portions 95 and 99 are connected with atransverse end band 105. The side portion 91 is tilted upwardly on itsouter edge 106 to assist in leading a plug blade into receptacle 25. Acenter strip portion 107 is interposed between the side portions 91 and93 and is disposed below the center plane 33. The center strip portion107 includes a pair of oppositely disposed end portions 111 and 113which angle longitudinally outwardly from one another and upwardly tothe center plane 33. The end portion 113 is coplanar with, and joiningto, the end portion 81 and the upper end of the end portion 111 isconnected to the end band 105.

A connector tab, generally designated 115, is joined adjacent the leftend band 105 and includes oppositely disposed upturned sides 117 and119.

The cube tap T is manufactured by attaching one strip S to a positivelead 121 and a second strip S to a negative lead 123. Such attachment isaccomplished by inserting the respective bare wires of the leads 121 and123 into the respective connector tabs 115, and then bending the sides117 and 119 inwardly over such wires. The strips S are then placed in amold with the respective receptacles 21, 23 and 25 disposed in side byside relation, and plastic is then injected into the mold to form thebody of the cube tap T.

A plug (not shown) is connected with the cube tap T, by inserting theplug blades into a pair of passages P and when the leading tips of suchblades reach the respective outside confronting edge 52, or 106 of therespective side portion 37, 67 or 91, such tips will be led into therespective receptacle 21, 23 or 25. When the plug blade (not shown)passes into the respective receptacle the cooperating pair of sideportions and center strip portion will be spread apart. The side andcenter strip portions will be bowed outwardly from the center plane 33and the respective resilient angled end portions will assume a moreupright orientation to widen the receptacle. It will be clear that thefully inserted plug blade will be held securely in, and firmlycontacting, the respective receptacle, thus preventing accidentaldisconnection of the cube tap T and plug (not shown).

In addition to securely holding the mating plug blade (not shown), aparticular advantage of this invention is that the overall length of theentire three receptacle strip S is relatively short, thus enabling thecube tap T itself to be relatively compact in size.

Various modifications and changes may be made with regard to theforegoing detailed description without departing from the spirit of theinvention.

We claim:

1. An elongated electrical contact strip for use in a cube tap andadapted to receive like polarity prongs of first and second plugs, saidcontact strip comprising:

a first receptacle for receiving a prong of said first plug andincluding;

a first side portion, offset above the longitudinal center plane of saidcontact strip, and having oppositely disposed first and second endportions, which extend downwardly to said center plane;

a first central strip portion offset below said center plane and havingoppositely disposed third and fourth end portions which extend upwardlyto said center plane;

a second side portion substantially coplanar with said first sideportion and having oppositely disposed fifth and sixth end portionswhich extend downwardly to said center plane;

said first side, central, and second side portions cooperating to definea transverse prong passage for tightly receiving said prong of said oneplug;

a second receptacle, disposed at one end of said first receptacle, forreceiving a prong of said second plug and including;

a third side portion disposed on the same side of said strip as saidfirst side portion, offset below said center plane, and havingoppositely disposed seventh and eighth end portions, which extendupwardly to said center plane, said seventh end portion being coplanarwith said first end portion and joined to a portion thereof;

a central strip portion adjacent the inner side of said third sideportion, ofiset above said central plane, and having ninth and tenth endportions which extend downwardly to said center plane, said ninth endportion being coplanar with said third end portion and having a portionjoined therewith, the remainder of said ninth end portion beingconnected with said first end portion;

a fourth side portion coplanar with said third side portion and disposedon the same side of said strip as said second side portion, and havingeleventh and twelfth end portions which extend upwardly to said centerplane, said eleventh end portion being coplaner with said fifth endportion and having a portion joined therewith, the remaining portionofsaid eleventh end portion being connected to said third end portion;

said third side, second central, and fourth side portions cooperating todefine a transverse prong passage which tightly receives the prong ofsaid second plug.

2. An electrical contact strip as set forth in claim 1 wherein saidfirst side portion is canted upwardly on its outside edge to assist inleading a plug prong into said first receptacle.

3. An electrical contact strip as set forth in claim 1 wherein saidthird side portion is canted downwardly on its outer edge to guide aplug prong into said second receptacle.

4. An electrical contact strip as set forth in claim 1 wherein the plugprong receiving passages formed by said first and second receptacles aresmaller in cross section than the cross section of the plug prongs to bereceived and wherein said end portions are at an angle from the verticaland are sufiiciently resilient to enable said respective cooperatingside and center strip portions to be spread apart by said plug prongswhereby said respective' cooperating side and center strip portions willbe urged inwardly by said respective end portion to tightly hold saidplug prong.

5. An electrical contact strip as set forth in claim 4 wherein saidfirst side portion is canted upwardly on its outside edge to assist inleading a plug prong into said first receptacle.

6. An electrical contact strip as set forth in claim 4 wherein saidthird portion is canted downwardly on its outer edge to guide a plugprong into said second receptacle.

References Cited UNITED STATES PATENTS 3/1966 Miller 339-157 11/1967Rodgers 339-498 US. Cl. X.R.

